Pregnancy/Lactation

Interactions

Adverse Reactions

None well documented.

Toxicology

Sea buckthorn has been used as a food in Asia and in Europe. Toxicological studies in animals suggest seed oil and oil from the fruit's soft parts are safe. Acute and chronic toxicity of blood, liver, and heart as well as mutagenicity and teratogenicity of sea buckthorn oils have been studied.

Botany

Sea buckthorn is a medium-sized, hardy, deciduous shrub that grows 2 to 6 m in height. It is found along riversides, in mountainous areas, and in sandy and gravel ground at elevations of 3,300 to 4,500 m. The bark is thick and rough. Each leaf is elongate-oblanceolate or elongate-spatulate, green at the top, and silver-ash green on the underside. It flowers in April and the sour, pearl-shaped, yellowish-orange fruits are collected from August to October. There are 9 described subspecies. 1 , 2 , 3 , 4 , 5

The plant is naturally distributed in Central Asia, in Europe from the Black Sea coast to the Alps, and along the shores of northwestern Europe. It also is found in Canada and the United States. 3

History

Sea buckthorn has a rich history of use in treating numerous medical conditions. It has been called a wonder plant in many Asian countries, including China, India, and Pakistan. The berries have been used for more than 1,000 years in Tibetan and Indian systems of medicine. In traditional Chinese medicine, it has been used to aid digestion and treat cough, circulatory disorders, and pain. 1 , 6 , 7

Because of their hemostatic and anti-inflammatory effects, the fruits are added to prescriptions in Indian and Tibetan medicine to treat pulmonary, GI, cardiac (eg, ischemic heart disease), blood, hepatic, and metabolic disorders. Ancient Tibetan medical literature documents the use of sea buckthorn for fever, inflammation, toxicity, abscesses, cough, colds, clearing sputum, laxative effect, tumors (particularly in the stomach and esophagus), and gynecological diseases. 1 , 2 The flowers are used as a skin softener in Tajikistan. 1 In Mongolia, extracts from the leaves and branches of the plant are used medicinally to treat colitis and enterocolitis in humans and animals. In Middle Asia, the leaves are used to treat GI and skin disorders, and topically applied to treat rheumatoid arthritis. 1 , 2 , 6

In Russia, the oil from the seeds and fruits was used topically to treat chronic dermatoses, eczema, psoriasis, lupus erythematosus, burns, frostbite, and cervical erosion. Oil from the fruit has been used to treat thrombosis. Oil extracts have been used in ophthalmology to treat keratitis, trachoma, conjunctivitis, and injuries or burns of the eyelid. 1

As an economic resource, sea buckthorn is used in a range of products, including oil, juice, cosmetics, shampoos, and as a food additive to candies and jellies. It has been planted extensively to help prevent soil erosion. 8 , 9

Chemistry

Flavonols in the leaves, fruit, or juice of sea buckthorn 1 , 10 , 11 , 12 , 13 are noted because of their antioxidant and anticarcinogenic activity. Most occur as C-3 glucosides, rutinosides, and sophorosides.

Flavon-3-ols found in the juice of sea buckthorn include (+) catechin (and +/- gallocatechin) and (-) epicatechin.

Tocopherols and tocotrienols in the fruit or seeds of sea buckthorn, 1 , 8 , 15 collectively known as vitamin E, have antioxidant activity. α-Tocopherol has the highest antioxidant activity and is the most abundant tocopherol, comprising approximately 76% to 89% of the berry.

Carotenoids found in the fruit of sea buckthorn 1 , 16 , 17 , 18 may decrease the risk for age-related macular degeneration and include α-, β-, and γ-carotene; lycopene; zeaxanthin; zeaxanthin dipalmitat; and β-cryptoxanthin palmitate. The antioxidant activity is more potent with extracted sea buckthorn oil because of higher carotenoid levels. Organic acids in the juice of sea buckthorn 1 have been identified as oxalic, citric, tartaric, malic, quinic, and ascorbic acid.

Fatty acid composition differs between the seed oil and soft parts of the fruit. The seed oil contains linoleic, α-linoleic, oleic, palmitic, stearic, and vaccenic acids. The fruit contains palmitoleic, palmitic, and oleic acids. Sterols are found in 1% to 2% of the seed oil and 1% to 3% in the soft parts of the fruit as sitosterol, isofucosterol, campsterol, stigmastanol, citrostadienol, avenasterol, cycloartenol, 24-methylenecycloartanol, and obtusifoliol. 1 , 4 , 19

The efficacy of a carbopol gel containing an extract of sea buckthorn was examined in experimental skin wounds in rats. Biopsy revealed that epithelization was more intensive, and occurred earlier, and granulation tissue differentiation (mature collagen fibers, profuse vascularity) was quicker in rats treated with the gel extract. 25

Patients treated with the seed oil had increased levels of linoleic, α-linolenic, and eicosapentaenoic acids in plasma lipids. After 1 month of treatment, these patients reported improvement of atopic dermatitis symptoms, which correlated with an increase in α-linolenic acid in plasma lipids. The proposed mechanism of action for these positive effects was inhibition of the synthesis of the 4-series leukotrienes from arachidonic acid and an increased synthesis of the 5-series leukotrienes. Patients treated with the pulp oil had increased levels of palmitoleic acid ( P < 0.05) in plasma phospholipids and neutral lipids. However, the changes in palmitoleic acid did not correlate with symptom improvements. The pharmacological effects of the oils may be related to different mechanisms involving components other than fatty acids. No changes were detected in the levels of triacylgylcerols, serum total, and specific IgE. 26

Seed and pulp oil supplementation over 4 months did not lead to changes in the skin glycerophospholipids of 16 atopic dermatitis patients in a placebo-controlled, parallel, randomized, double-blind trial. 27

Clinical effects of the oil have been tested in 48 cirrhotic patients of Child-Pugh grade A and B treated with a sea buckthorn extract of 15 g by mouth 3 times daily for 6 months. Primary outcomes included measurements of cytokines and various blood parameters of liver fibrosis and liver function tests (eg, IL-6, TNFα, ALB, AST, ALT). Patients treated with sea buckthorn extract had reduced serum levels of laminin, hyaluronic acid, total bile acid, and collagen types III and IV. These results suggest that the seed oil of sea buckthorn may be useful for prevention and treatment of liver disease. 30

Effects on platelet aggregationIn vitro and animal data

Total flavones from sea buckthorn fruit prolonged thrombotic occlusion time in a mouse femoral artery thrombosis model. In the same study, total flavones inhibited platelet aggregation induced by collagen in a concentration-dependent manner but did not affect aggregation induced by arachidonic acid and adenosine diphosphate. Mechanism of action remains unclear but may be caused by suppression of arachidonic acid synthesis by collagen receptor stimulation. 31

The effects on sea buckthorn juice on risk factors for CV disease were studied for 8 weeks in 20 men in a double-blind, placebo-controlled trial. Patients consumed 300 mL sea buckthorn juice or placebo by mouth daily for 8 weeks. Although not statistically significant, sea buckthorn juice supplementation appeared to increase plasma HDL cholesterol and decrease the susceptibility of LDL to oxidation. 33

In a study of 88 patients, total flavones in sea buckthorn did not alter the sympathetic activity in treatment of hypertension when compared with patients being treated with nifedipine and extended-release verapamil. 34

Protection against whole-body irradiation has been reported in mice; an alcoholic extract of the berries rendered nearly 82% survival as compared with no survival in untreated irradiated control. In liver, the oil from the berries inhibited the Fenton reaction and radiation-mediated generation of hydroxyl radicals, and superoxide anion mediated nitroblue tetrazolium reduction and FeSO 4 -mediated lipid peroxidation. The radioprotective effects may be associated with any of the following actions: free-radical scavenging, acceleration of stem cell proliferation, immunostimulation, and direct modulation of chromatin organization. 2 , 37 , 38

Sea buckthorn oil may stimulate the recovery of hematopoiesis after chemotherapy. Blood cell counts in mice with myelosuppression fed with oil from sea buckthorn exceeded those in the control group and mortality decreased. 43

Other pharmacological effects

Flavonoids from seed and fruit extracts of sea buckthorn inhibited glycometabolism and reduced serum glucose, serum cholesterol, and serum triglycerides in mice. The seed oil from sea buckthorn may reduce infarction volume after occlusion of middle cerebral artery in rats and protect against ischemic cerebral infarction. Sea buckthorn juice may protect against learning and memory changes caused by lead-induced neurotoxicity in mice. Flavones from sea buckthorn promoted healing of the patellar tendon in a rat model by enhancing collagen deposition and muscle fiber recovery. Administration of a sea buckthorn leaf extract on the same day or 5 days prior to inducing inflammation in the right hind paw of rats reduced the inflammation in a dose-dependent manner when compared with controls. 44 , 45 , 46 , 47 , 48

Dosage

Doses of seed oil taken orally in clinical trials ranged from 5 to 45 g daily for 4 to 6 months. 26 , 30 , 32 Juice has been administered to volumes of 300 mL daily over 8 weeks. 33

Interactions

Sea buckthorn juice decreased the genotoxic effects of cisplatin on bone marrow and sperm cells in mice at a dose of 1.2 mg/kg. 50

Adverse Reactions

None well documented.

Toxicology

One review article documents sea buckthorn's history of use as a food in Asia and in Europe. Research from toxicological studies using animal models suggests seed oil and oil from the fruit's soft parts are safe. These studies also examined acute and chronic toxicity of blood, liver, and heart as well as mutagenicity and teratogenicity of ingested oils. 4